Iris Color Distribution and Its Relation with Refractive Errors, Amblyopia, and Strabismus in Children

Background: Despite the presence of various reports regarding the association between iris color and some ocular diseases in adults, there is little evidence of such relation in children. Objectives: Determine the distribution of iris color in seven-year-old children in Iran and its relation with refractive errors, amblyopia, and strabismus. Methods: In this cross-sectional study, 3414 seven-year-old school children were selected from six cities through multistage random sampling. The iris color in this study was classified into dark brown, medium brown, light brown, yellow, green, gray, and blue. All subjects were examined for visual acuity, refraction, and binocular vision assessment. Results: Of the 3414 selected samples, 3030 children participated in the study (89 response rate). The prevalence and 95 confidence intervals (CI) of myopia, hyperopia, and astigmatism was 3.03 (2.30 - 3.99), 6.20 (4.40 - 8.65), and 17.42 (13.30 - 22.48), respectively. Amblyopia was detected in 1.85 (1.10 - 3.12) and the prevalence of strabismus was 2.50 (1.86 - 3.35). Dark brown was the most common iris color at 52.50 (50.06 - 54.93) in boys, 46.07 (43.49 - 48.68) in girls, and 49.50 (47.72 - 51.28) in the total sample population. According to logistic regression results, the odds ratio (95 CI) of hyperopia was 0.3 (0.15 - 0.6) in those with medium brown iris color and 0.23 (0.1 - 0.47) in those with dark brown eyes compared to the group with yellow or green iris colors. Conclusions: Approximately 90 of the studied subjects had dark or medium brown eyes. Given that people with yellow or green eyes are at a higher risk of hyperopia, it is recommended that these individuals be given attention in this regard during screening, and the presence of hyperopia be taken into consideration during refraction examinations for these children. © 2019, Journal of Comprehensive Pediatrics.